The present invention, in general, relates to distribution and usage of digital content over mobile devices. In particular, this invention relates to distribution and management of Java based digital content (applications) that have digital rights ascribed to them.
With rapid developments in wireless technologies and with the onset of technically superior mobile devices and networks, distribution of digital content, which was predominantly being carried out only on the Internet, is now significantly being done over mobile networks as well. The new-generation mobile devices include mobile phones, Personal Digital Assistant (PDA), Laptops, etc with digital applications such as calendar, games, and the like. The new-generation mobile networks have a high data-transfer rate and, at the same time, support a greater number of mobile users. Thus, developments in mobile network technologies and superior mobile devices have enabled the transfer of digital content over wireless networks.
Broadly speaking, the transfer of digital content over the mobile networks is done in the following manner. Initially, a user requests for download of digital content from his/her mobile service provider. A content provider, which is in contact with a mobile service provider, hosts the downloadable digital content. The user then downloads the requested digital content on his/her mobile device through the mobile service provider. However, as the present mobile devices have the capability to distribute (or forward) the digital content to other mobile devices, a mobile device user can potentially distribute the downloaded digital content to numerous other mobile device users. This means that digital content such as games, graphics, utilities (such as a currency converter) and the like can be forwarded to other users if there is no protection for preventing such distribution. Such uncontrolled distribution is not desirable to the content provider (of the “unprotected” digital content). In order to explain this point more clearly, consider an example of a mobile service provider who provides mobile games for some payments by the user. If the game is “unprotected”, then the same may be forwarded and used by numerous other mobile users who have devices capable of receiving and using the game. This is economically undesirable for the content providers. Further, such distribution also leads to problems of licensing and copyright violations. Indeed, the content providers are wary of such problems and these problems are deterring content providers from hosting “rich” digital content for mobile devices without taking necessary steps towards protecting the digital content. It is desirable that the digital content provided by the content provider be protected from such misuse. That is, it is desirable that every mobile user using the digital content pays the content provider in some way to compensate the content provider. In order to address the problem of uncontrolled distribution of digital content, content providers rely on Mobile Digital Rights Management (Mobile DRM) techniques that protect digital content, and allow only authorized usage of the digital content.
Mobile DRM provides a secure infrastructure for the preparation, transmission, and prevention of misuse of the protected digital content. Thus content providers before making digital content available for usage protect the digital content with DRM Packages. A mobile user now cannot indiscriminately transfer this “protected” digital content to other mobile users without the requisite payments being made by the other users as well.
With the implementation of Mobile DRM, the existing state of technology for mobile networks works as follows: a user requests for download of digital content from his/her mobile service provider. Upon receiving the request, the user is prompted to pay for the digital content that he/she intends to download. After receiving the necessary payments, the mobile service provider forwards the digital content (which may have digital rights associated with it) to the user. The user is then able to download the requested digital content on his/her mobile device. The associated digital rights prevent the unauthorized distribution and usage of the downloaded digital content from mobile devices.
The basic requirements of a Mobile DRM system are scalability, provision of security to digital content and ease of implementation. To meet the scalability requirement, the Mobile DRM system should be able to handle diverse types of rights that may be issued by different issuers (for instance different content providers).
For the requirement for provision of security to digital content, the Mobile DRM system must prevent illegal use (such as unauthorized copying, alteration, and distribution) of the digital content. The system should also ensure that the digital content is used according to the rights assigned to it by the content provider.
In the above setup, it is usually the prerogative of the content provider to assign rights to the digital contents and prevent possible misuse while determining a pricing structure for the digital content at the same time. Assigning all the rights to the digital content at the content provider's end may lead to inflexibility in terms of the way the digital content is used in the future. For example, the content provider may fix the pricing of a song and the number of times it can be played without payment. Once this is fixed, the mobile service provider, who distributes this digital content, may not be able to change the above attributes for different user requirements. Further, the content provider may not want the digital content to be copied from one user to another. This may prevent the further distribution of digital content in an authorized manner from one user to another (called superdistribution) and eventually will limit the number of users of the digital content.
For meeting the ease of implementation requirement, the Mobile DRM should require minimal installation of software on the user's mobile device for the implementation of Mobile DRM policies. A new user, therefore, should require minimal installation of software before he/she is able to download and distribute the protected digital content. This is advantageous for the mobile service provider as it increases the ease with which the mobile service provider can get new mobile device users to use the services provided by the mobile service provider. There are some solutions available in the art that try to address the above-mentioned requirements. Content Policy System (CPS), a product from Beep Science AS, Norway is a Digital Rights Management solution for mobile service providers. This is a server-side solution that enables the mobile service provider to act as a payment collector for their own and partners' digital content, and ensures that copyright restrictions are enforced. The product also allows for superdistribution of digital content amongst users.
Another product RIGHTS|SYSTEM from Intertrust Technologies Corporation, California, USA supports Digital Rights Management of any kind of digital content. The associated technology offers its customers the choice of choosing their business model and distribution method. In this system, the digital content is assigned rights through a packager before it is distributed. The user can then buy the digital content and rights to its use by making appropriate payments to the retailer of the digital content. The product also allows for superdistribution of digital content amongst users. The product requires the digital content to be protected and be assigned rights to it before it is sent to the mobile service provider for further distribution. This inhibits the mobile service provider from applying flexible charging policies to the digital content.
In addition to the drawbacks mentioned above, both the products mentioned above are directed more towards DRM of computer networks rather than that on mobile networks.
U.S. patent application No. US20010052077A1, titled “Universal Mobile Id System And Method For Digital Rights Management”, allows client devices and users to receive customized digital content from service provider's servers irrespective of service provider's prior knowledge of clients' configurations or users' preferences. The disclosed invention also prevents an authorized user from passing on digital content to another user who is not authorized to access the paid digital content. The information about the user and his/her mobile device is captured in a Universal Mobile ID (UMID) that enables the service provider's servers to customize digital content for clients for whom no prior knowledge is available. The application prevents an authorized user from passing on digital content to another user, who is not authorized to view the paid digital content. This is not desirable as the mobile service provider here limits the distribution of the digital content, thereby limiting the total number of users who may possibly pay for the digital content. Further, this requires every mobile device to be given a UMID. This again requires new users to formally “register” with the mobile service provider thereby restricting the total number of possible users.
World patent application number WO03003173A1, titled “Digital Rights Management”, discloses a method for digital rights management in a network. A DRM server is responsible for issuing rights to requesting DRM clients. Once a DRM client obtains the rights, the rights are locked to a pseudo- or semi-unique node identifier obtained or calculated from the characteristics of the client. Rights of access to DRM-protected digital content are then granted subject to rights specifications and node identifier. This patent application attempts to grant rights of use to each mobile device instead of assigning rights to each application. This is not desirable as this leads to inflexibility in the implementation of DRM policies. It is desirable that the implementation of DRM policies is application (or digital content) based rather than user-based.
World patent application number WO03005145A2, titled “Digital Rights Management In A Mobile Communications Environment”, provides a method to control the access, copying and/or transfer of digital contents by mobile, wireless devices using digital vouchers. The content provider can specify the terms and conditions for distribution of the primary digital content. A digital voucher is similar to a license that is stored in the mobile or wireless device. The digital voucher authorizes the mobile device to access digital content that may be located elsewhere in the network. A DRM agent that is present on a server computer generates the voucher. A user can download a copy of the digital content that he or she is allowed to view according to the terms and conditions of the digital voucher using the mobile device. A user can distribute digital content to others based on the conditions in the digital voucher, that is, if the user has sharing authorization. The application requires the digital voucher to be present on the mobile device. This is not desirable, as this requires some kind of “registration” of the mobile device with the mobile service provider. Further, the implementation of charging policies is done when the digital voucher is created. Instead, it is desirable that the charging policies be implemented at the instant of download, giving greater flexibility to the mobile service provider.
In addition to the points mentioned above, it is also desirable that the DRM system need not have any DRM agent software running on the mobile device itself to implement DRM policies. Another desirable feature, which is not provided in existing systems, is that of applying charging policies to the digital content at runtime while it is being downloaded by a user on the mobile device. This enables the mobile service provider enforce multiple charging policies for the same kind of digital content depending on different business models.
Hence, there is a need for a system for data distribution over a mobile network that allows charging of digital content as it is being delivered to the mobile device. This system must also be able to safeguard the rights of the content providers during the process of superdistribution of the digital content. Further, there is a need for a system that does not require any kind of DRM agent on the mobile device itself to implement DRM policies. Additionally, there is also a need for a system that does not require the content provider to assign fixed rights to all the digital content for DRM enforcement before it is ready for distribution through the mobile service provider. Therefore, the same digital content can be issued different rights for different users. Further, there is a need for a system that allows for the update and re-issue of a license for the same digital content.